UvA-DARE (Digital Academic Repository) Translating Flowering Time From Arabidopsis thaliana to Brassicaceae and Asteraceae Crop Species Leijten, W.; Koes, R.; Roobeek, I.; Frugis, G. DOI 10.3390/plants7040111 Publication date 2018 Document Version Final published version Published in Plants (Basel, Switzerland) License CC BY Link to publication Citation for published version (APA): Leijten, W., Koes, R., Roobeek, I., & Frugis, G. (2018). Translating Flowering Time From Arabidopsis thaliana to Brassicaceae and Asteraceae Crop Species. Plants (Basel, Switzerland), 7(4), [111]. https://doi.org/10.3390/plants7040111 General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). 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UvA-DARE is a service provided by the library of the University of Amsterdam (https://dare.uva.nl) Download date:07 Oct 2021 plants Review Translating Flowering Time from Arabidopsis thaliana to Brassicaceae and Asteraceae Crop Species Willeke Leijten 1 , Ronald Koes 2, Ilja Roobeek 1,* and Giovanna Frugis 3,* 1 ENZA Zaden Research & Development B.V., Haling 1E, 1602 DB Enkhuizen, The Netherlands; [email protected] 2 Swammerdam Institute for Life Sciences (SILS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands; [email protected] 3 Istituto di Biologia e Biotecnologia Agraria (IBBA), Operative Unit of Rome, Consiglio Nazionale delle Ricerche (CNR), via Salaria Km. 29,300, 00015 Monterotondo Scalo, Roma, Italy * Correspondence: [email protected] (I.R.); [email protected] (G.F.); Tel.: +31-(0)228-350100 (I.R.); +39-06-9067-2889 (G.F.) Received: 1 November 2018; Accepted: 13 December 2018; Published: 16 December 2018 Abstract: Flowering and seed set are essential for plant species to survive, hence plants need to adapt to highly variable environments to flower in the most favorable conditions. Endogenous cues such as plant age and hormones coordinate with the environmental cues like temperature and day length to determine optimal time for the transition from vegetative to reproductive growth. In a breeding context, controlling flowering time would help to speed up the production of new hybrids and produce high yield throughout the year. The flowering time genetic network is extensively studied in the plant model species Arabidopsis thaliana, however this knowledge is still limited in most crops. This article reviews evidence of conservation and divergence of flowering time regulation in A. thaliana with its related crop species in the Brassicaceae and with more distant vegetable crops within the Asteraceae family. Despite the overall conservation of most flowering time pathways in these families, many genes controlling this trait remain elusive, and the function of most Arabidopsis homologs in these crops are yet to be determined. However, the knowledge gathered so far in both model and crop species can be already exploited in vegetable crop breeding for flowering time control. Keywords: Brassicaceae; Asteraceae; flowering time; photoperiod; vernalization; ambient temperature; gibberellins; age; plant breeding 1. Introduction The switch from vegetative stage to flowering is essential for plant reproduction, and flowering time diversity has adaptive value in natural populations [1]. The time at which flowering occurs plays a major role in agricultural production as it affects the quality and quantity of leaf, flower, seed and fruit products, ease of harvest and marketing. Shifting the seasonal timing of reproduction is a major goal of plant breeders to develop novel varieties that are better adapted to local environments and changing climatic conditions [2]. Over the last few years, climate underwent significant changes, such as relatively mild winters, dry and warm summers, and more heavy rain fall in spring and autumn. All of those changes affect plant growth and flowering time. Besides natural occurring climate change, adapting varieties to new environments makes crop production more flexible [2]. To produce varieties that are more robust and predictable in flowering time is also a desirable trait for reliable production. Obtaining varieties with increased yield is also a major breeding goal, and will enhance food production within the same amount of land in a world where the population is growing, Plants 2018, 7, 111; doi:10.3390/plants7040111 www.mdpi.com/journal/plants Plants 2018, 7, 111 2 of 42 and demanding more food production. However, yield is influenced by several factors, including premature bolting (see Glossary in Table1) during crop production, and therefore, a prolonged vegetative phase will increase yield for leafy crops that are harvested before the transition to the reproductive phase. Table 1. Glossary of main terms as used in the review. Term Definition flowering time the switch from plant vegetative growth to reproductive development bolting rapid elongation of the inflorescence/flowering stem plants that complete their entire life cycle from seed to flower within one year and annuals are characterized by short vegetative phase biennials plants which require two years to complete their life cycle, plants that survive for several years and restrict the duration of reproduction by perennials cycling between vegetative growth and flowering; perennials are characterized by prolonged vegetative phase that can last from a few weeks to several years population of cells located at the tip of the shoot axis that produce lateral organs, shoot apical meristem (SAM) stem tissue and regenerates itself a meristem that underwent transition from vegetative to reproductive fate and can inflorescence meristem (IM) produce floral meristems floral meristem (FM) group of cells responsible for the formation of floral organs plants that flower faster under a particular photoperiod but will eventually flower facultative photoperiod under all photoperiods (also called “quantitative”) obligate photoperiod plants that flower only under a particular photoperiod (also called “qualitative”) long days day length more than about 12 h, usually 16 h light and 8 h dark periods short days day length less than about 12 h, usually 8 h light and 16 h dark periods Double Haploid (DH) chromosome doubling of haploid cells to produce genetically homozygous plants observational study of a genome-wide set of genetic variants in different individuals genome-wide association study (GWAS) that occur more frequently in correlation with a specific trait, identifying inherited genetic variants associated with a trait homolog a gene related to a second gene by descent from a common ancestral DNA sequence genes in different species that evolved from a common ancestral gene by speciation; ortholog normally, orthologs retain the same function in the course of evolution paralog genes related by duplication within a genome that may evolve new functions maturity the state of being fully developed or full grown a state or condition of the plant in which everything is regular, homogeneous, uniformity or unvarying predictable always behaving or occurring in the way expected is a characteristic of being strong that, when transposed into a system, it refers to the robust ability of tolerating perturbations and remain effective (or Quantitative Trait Locus), is a locus (section of DNA) which correlates with QTL variation of a quantitative trait in the phenotype of a population of organisms cold treatment needed to get many perennials to flower; usually the minimum period vernalization is six to twelve weeks at 4 ◦C spring types plants which flower early without vernalization plants which have an obligate requirement for prolonged periods of winter types cold temperatures semi-winter types plants which require mild vernalization and lack frost hardiness Controlling flowering time would therefore help grow crops in all seasons to speed up the production of new hybrids and produce high yield throughout the year. Early bolting potentially limits vegetative growth and can severely decrease yield, while non-flowering inhibits seed production. The timing of bolting and flowering are especially important for vegetable crops. For cauliflower and broccoli, synchronization of flowering is essential as the plants are harvested in the inflorescence meristems phase (curds). For lettuce, plants flower early when grown at high temperature. Early stages of bolting are not visible, but the flavor changes more towards bitter. Therefore, late bolting is preferred to enhance yield without the bitterness. In the past, selection for flowering time was based on plant phenotyping in the greenhouse or in the field. The increasing availability of crop genetic and genomic resources, and the current knowledge on both gene function and natural genetic variation, are of great value and can be used in breeding. The development of trait specific markers, e.g., based on QTL (see Glossary